An opening and closing apparatus for an opening and closing body of a vehicle. The opening and closing apparatus includes a reciprocating member connected at its connecting portion to a motor so as to be moved to reciprocate along a plane perpendicular to a hinge shaft, the reciprocating member having a side surface parallel with the plane perpendicular to the hinge shaft. A connecting member is provided having a first end section pivotally attached to an end portion of the reciprocating member, and a second end section fixed to the opening and closing body. A deflection-suppressing device is provided to a stationary body connected to the vehicle body. A part of the side surface of the reciprocating member is slidably contacted with the deflection-suppressing device and is located between the connecting portion of the reciprocating member and the connecting member.