To provide a solid state imaging apparatus which surely guides a lens holder in a direction of an optical axis and can be downsized.

The solid state imaging apparatus has a first lens unit 10 in which a group of lenses 13a to 13d for imaging an optical image on an image pickup surface of an imaging apparatus. The first lens unit 10 comprises the lens holder 11 for holding the group of lenses 13a to 13d and a lens-barrel 12 which is engaged with the lens holder 11 to support the lens holder 11 in the optical axial direction. The lens-barrel 12 has a guiding part 123 on both sides in the optical axial direction of the lens with a female screw portion 122 as a boundary. The guiding part 123 has internal peripheral surfaces 121b and 121c which are parallel to each other in the optical axial direction of the lens-barrel 12l and are different in internal diameter. The lens holder 11 is guided coaxially to a holder base 12 and fixed with an adhesive by outer peripheral surfaces 112b and 112c slidably contacting the internal peripheral surfaces 121b and 121c of the guiding part 123.