A wing flapping apparatus includes a motive power source; a power transmission mechanism; and a wing unit driven by the power transmission mechanism. The power transmission mechanism includes a rotation transmission member configured to rotate upon reception of motive power transmitted from the motive power source; a slider configured to linearly reciprocate in an X-axis direction upon reception of the motive power transmitted from the rotation transmission member and a rotating body configured to reciprocate in a rotation direction upon reception of the motive power transmitted from the slider. The wing unit is configured to swing such that its distal end moves approximately in the X-axis direction as the rotating body reciprocates in the rotation direction. The power transmission mechanism further includes a pair of crank arms each configured to connect the rotation transmission member and the slider. The pair of crank arms each has: one end rotatably connected to the rotation transmission member and the other end rotatably and slidably connected to the slider.