To provide a lifting platform apparatus capable of arbitrarily changing the height of a working platform and enabling the user to easily climb up and down the lifting working platform.

This lifting platform apparatus 1 includes a base 4, the working platform 6 installed on the base 4 through a link mechanism 5, wheels 2 attached to the base 4 side, a ladder body 8 installed between the base 4 and the working platform 6, and a guide member 89 serving as a grip section provided to the working platform 6. The ladder body 8 includes a slide member 90 serving as a slide body slidably provided to the guide member 89, and is fixed to the base 4 side through the engagement by a lock means 117 installed on the slide member 90 side and a through section 44 for fixing the erected state installed on the base 4 side using the slide member 90 as a fixing means. Consequently, the ladder body 8 is extendable when the working platform 6 is lifted.