An isolator including: a main body case including a box-shaped working space and provided with an inserting portion of a work hand on a front surface thereof; an illuminating device that illuminates the inside of the main body case; and an air-conditioning device that performs air conditioning inside the main body case, the illuminating device having a plurality of point light sources that are arranged substantially linearly in the main body case, the main body case including a back plate or a bottom plate, at least one of the back plate or the bottom plate being constituted by a metal plate, and a rolling direction of the back plate or the bottom plate constituted by the metal plate being a direction substantially orthogonal to an arrangement direction of the plurality of point light sources.