Brain inspired memory prototypes, such as atomristors, are touted as next generation two terminal memories for neuromorphic computation. To make rapid progress toward developing such atomic scale memory, a facile technique to fabricate atomristor prototypes has to be developed. In this work, one such simple and lithography free technique to fabricate an atomristor prototype using photoexfoliated monolayer molybdenum di-sulfide (MoS2) is illustrated. Resistive switching characteristics of the atomristor were demonstrated by applying a write voltage pulse of 10 (SET) and −5 V (RESET) for 100 s between the active tantalum di-sulfide (TaS2) and inert indium tin oxide electrodes. During the SET process (ON state), the Ta2+ ions from the active electrode diffuse through monolayer MoS2 to create a number of parallel conducting channels. The persistence of the conducting channel even after removing the SET bias drives the atomristor to the low resistance state. On applying the “RESET” bias, the device resistance increased by a factor of five possibly due to the rupturing of the conducting channel. On cyclically applying the “SET” and “RESET” biases, the device was switched between low and high resistance states with excellent repeatability. Interestingly, it was also observed that the switching ratio increased on increasing the SET bias making this device a promising candidate for realizing tunable write once read many (WORM) memory devices.