engagement recesses 26 a to 26 d in the first embodiment each engagement recess 31 a 31 b 31 c or 31 d has a rear side inclined surface 32 a and a front side inclined surface 32 b a slope of the rear side inclined surface 32 a relative to the top surface 20 b is larger than a slope of the front side inclined surface 32 b relative to the top surface 20 b more specifically an angle u03c6a greater than zero degree defined between the rear side inclined surface 32 a and the top surface 20 b is greater than an angle u03c6b greater than zero degree defined between the front side inclined surface 32 b and the top surface 20 b in the state where the engaging member 22 is in engagement with one of the engagement recesses 31 a to 31 d when the user presses or pushes the drawer 11 in the storing direction s the engagement between the engaging member 22 and the engagement recess 31 a 31 b 31 c or 31 d exhibits a first type of engaging force against the user 39 s action of pushing the drawer 11 in the storing direction s similarly in the state where the engaging member 22 is in engagement with one of the engagement recesses 31 a to 31 d when the user pulls or draws the drawer 11 in the drawing direction d the engagement between the engaging member 22 and the engagement recess 31 a 31 b 31 c or.