To provide a storage shed easy in mounting work, having a tray for avoiding damage to an inner wall of a storage room.

In the storage shed, both right and left protruded parts 37 are matched to guide parts 50 in the state of connecting a cover base 31 to an opening/closing plate 32. When the protruded parts 36 are thrust by a thrust face 53, the elasticity of a thin plate part 38 is utilized to inwardly turn both right and left protruded parts 37 to be displaced, thus avoiding locking portions 39 of both right and left protruded parts 37 from being strongly pushed against the guide parts 50. At the position of mounting the cover base 31, the protruded parts 37 are outwardly turned with the elasticity, displaced and restored to enter into recessed portions 54 of the guide parts 50.