Lens unit and in-vehicle camera

A lens unit comprising:

• a lens group in which a plurality of lenses are aligned along an optical axis direction of the lenses;
• a lens barrel that integrally supports the lens group;
• and an annular elastic member disposed between the lenses in at least one position of the lens group and in contact with both of the lenses, wherein
• the lenses that sandwich the annular elastic member in the optical axis direction have respective abutment surfaces in abutment with each other in parts of outer circumferential surfaces facing each other,
• one of the lenses that sandwich the annular elastic member in the optical axis direction includes a recess having an annular shape to be recessed in the optical axis direction on an outer circumferential surface on an outer circumferential side of the abutment surface,
• the annular elastic member is provided in a compressed state in the optical axis direction in the recess, and
• the annular elastic member presses all the lenses disposed on an object side of the annular elastic member toward an end portion of the lens barrel on the object side, also presses all the lenses disposed on an image side of the annular elastic member toward an end portion of the lens barrel on the image side, and thus absorbs rattling that occurs in association with a relative movement of the lens barrel and the lens group in the optical axis direction caused by a temperature change.