A printed substrate holding device includes: a base member including a recess portion including: a bottom portion; and a side wall portion provided in the bottom portion; and a printed substrate held in the recess portion and having a rigidity, wherein the side wall portion includes a holding portion holding a first surface of the printed substrate, the bottom portion includes a supporting portion supporting a second surface of the printed substrate, the printed substrate slides on the bottom portion and is inserted between the supporting portion and the holding portion, and is held in the recess portion, and the printed substrate is held in the recess portion while being bent.