A projection lens unit includes: a projection lens having a first optical system for focusing incident image light and also having a second optical system for magnifying and projecting the image light focused by the first optical system; a lens barrel member for accommodating the projection lens and having a small diameter portion in which a joining portion of the first and the second optical system is formed to be the thinnest; a holding member having a first holding face on which the small diameter portion is mounted; and a presser member having a second holding face which holds the small diameter portion together with the first holding face. The holding member is fixed to a housing on which the projection lens unit is mounted. The presser member does not protrude upward from the lens barrel member arranged in a dead space of the small diameter portion.