An image pickup apparatus having an optical path reflecting zoom lens system includes a zoom lens system, and an image pickup element which is disposed at an image side of the zoom lens system. The zoom lens system includes in order from an object side thereof a first lens unit G1 having a positive refracting power, which includes a reflecting optical member having a reflecting surface which reflects an optical path, a second lens unit G2 having a negative refracting power, a third lens unit G3 having a positive refracting power, a fourth lens unit G4 having a positive refracting power, and an aperture stop S which is disposed between the second lens unit G2 and the fourth lens unit G4. The first lens unit G1 has a position fixed with respect to a position of the image pickup element. At least the second lens unit G2 and the fourth lens unit G4 move and the zooming is carried out from a wide angle end to a telephoto end by changing a distance between each of lens units. The second lens unit G2 includes in order from the object side thereof, a negative lens, a positive lens, and a negative lens.