A wide-angle converter lens capable of being detachably mounted on an enlargement side of an imaging lens includes a first optical element, at least one optical element having negative refractive power, and at least one optical element having positive refractive power, wherein, when an average value of relative partial dispersions of the first optical element and all optical elements of which the sign of refractive power is the same as that of the first optical element is denoted by θgF_ave, a relative partial dispersion of the first optical element is denoted by θgF, and an Abbe number of the first optical element is denoted by νd, these numerical values satisfy appropriate relationships.