Bamboo is one of the plants that accumulates large amounts of silicon (Si) and potentially be utilized as a source of Si. Si plays a role in reducing abiotic and biotic stresses. This study aims to analyze the Si content in ash from various bamboo plant organs (leaves, stems and roots). Bamboo was taken from Klaten Regency, Central Java. The process of making ash used manual burning, followed by ashing using a furnace at 600 °C in temperature. Bamboo plant ash was analyzed using the AOAC method and confirmed by Energy Dispersive X-Ray Fluorescence Spectrometer (ED XRF), Scanning Electron Microscope (SEM) instruments and mapping to determine the composition of the oxide and SiO2 content. Analysis using the AOAC method showed that SiO2 content in bamboo leaf ash (76.88%) was higher than bamboo stem ash (48.43%) and bamboo root ash (56.28%). The results of ED XRF, SEM analysis and mapping showed that the main composition of bamboo plant ash was SiO2. SiO2 content of bamboo leaf ash (22.89%; 80.28%) was higher than bamboo stem ash (12.36%; 39.17%) and bamboo root ash (11.82%; 61.57%), respectively. The higher Si content in bamboo leaf ash was related to Si deposition in the leaf epidermis.