Staple removing device

A staple removing device comprising:

• a placement portion having a placement surface on which a paper bundle bound by a staple including a crown portion and a leg portion is to be placed;
• a rotating shaft extending from below the placement surface toward the placement surface;
• and
• a removal unit attached to the rotating shaft and rotating along a surface intersecting an axial direction of the rotating shaft, wherein
• the removal unit includes
• a tip portion to be inserted between a lower surface of the paper bundle placed on the placement surface and the crown portion,
• a middle portion connected to the tip portion and having an action surface to be in contact with the crown portion, and
• a base portion connected to the middle portion and supported by the rotating shaft,
• an upper surface of the base portion is located on the same plane as the placement surface or below the placement surface,
• the tip portion is located above the upper surface of the base portion, and
• an outer peripheral side edge of the middle portion extending along a rotation trajectory of the removal unit in a circumferential direction of the axial direction is formed by a convex arc shape when seen from the axial direction, and an inner peripheral side edge of the middle portion extending along the rotation trajectory of the removal unit is formed by a concave arc shape when seen from the axial direction.