An elevating mechanism of a projection apparatus includes a housing, a guide slot, an adjustable foot mount, at least one resilient member, and a sliding arm. The guide slot is formed on a surface of the housing and having multiple sections to form a sliding path. At least one section has multiple teeth, and a recess is formed between each two adjacent teeth. The sliding arm has a fixed end and a free end, the fixed end is fixed on the adjustable foot mount, and the free end is slidably coupled to the guide slot. When the sliding arm slides on the section having the teeth, the free end of the sliding arm engages with any of the recesses to hold the adjustable foot mount at a selected position.