restricted because, in general, the patterned electrode is fabricated by vacuum evaporation with a shadow mask. It is hard to obtain such a precision mask that can produce micron-level metal patterns; the smallest memory cells that have been obtained so far are around 100 µm. [4,[16][17][18][19][20][21][22][23] Another option for obtaining high memory density is multilevel recording. [24][25][26][27][28] Multilevel recording requires a stable and distinct multilevel between the highest and lowest recording levels and a high signal-to-noise ratio (SNR); in other words, a large difference between the highest and lowest levels, and a small fluctuation in each level. For example, to obtain four-times density (4 bits in a single memory cell), multilevel recording needs 2 4 = 16 distinguishable levels and, therefore, 16-times of an original SNR. More density by multilevel recording requires much larger SNR. In actual organic memory devices reported so far, the level fluctuation is very large, [3,26,[29][30][31][32][33] and it is difficult to obtain enough SNR to achieve multilevel recording. On the other hand, a half-size memory cell with the same SNR easily achieves four-times density. Therefore, reducing memory cell size, or preparing miniaturized electrodes, is very important to obtain high memory density.Photochromism is defined as a reversible change of molecular species and various properties of molecules-aggregation, film, composites, and/or bulk-including a crystal phase are changed as well as color. [34][35][36][37][38][39][40][41] Photochromic diarylethenes (DAEs) are well known as a series of photochromic molecules with very high stability in both isomerization states. [34,35] An interesting function of DAE is selective metal-vapor deposition. [42][43][44] Selective metal-vapor deposition signifies metalvapor atoms deposit on the colored surface generated by UV irradiation onto the DAE film but not on the colorless surface. Selective deposition originates in a large change in a glass transition temperature (T g ) of an amorphous DAE film based on photoisomerization. The core phenomenon of selective deposition is metal atom desorption from a low-T g colorless surface. Selective metal-vapor deposition can be applied to prepare fine metal patterns using maskless vacuum evaporation for electrical and optical devices. [45,46] In this article, we report a minute organic memory cell with a micron scale, in which an active memory layer is composed of a DAE-Cu composite film based on selective metal-vapor deposition.One of the major challenges in the field of organic electronics is miniaturization and integration of electrical components. Such miniaturization, however, has been restricted strictly so far because of the difficulty in fabricating minute electrodes on organic layers and their patterning. The conventional metal electrode has been fabricated generally using vacuum evaporation with a shadow mask, and the resolution of the shadow mask limits the electrode size. In this study, a minute organic memory cell fa...