To provide an opening/closing device which has a simple structure with a small number of components and can stably perform latch motion such as engaging and disengaging.

An opening/closing device includes a body part and a drawing 3 as an opening/closing component which is supported movably to the body part. A side frame portion 4 as a frame structuring body constituting at least a part of the drawing is integrally molded in a state connecting a latch piece 71 to the major portion 4M. An operation piece 6 is provided at a position where the drawing 3 engages with the latch piece 71. A latch reception part 81 is provided at a position where the body part faces to the latch piece 71. The latch reception part 81 engages with the latch piece 71 so as to lock the drawing 3 to the body part. By operating the operation piece 6, a part of the latch piece 71 is elastically deformed and the latch piece 71 is alienated from the latch reception part 81 to release the locking state.