PURPOSE: To provide a compact macro-lens having a relatively small delivering quantity in focusing, and capable of performing a high power photographing having a photographing distance to some degree.

CONSTITUTION: This lens is formed of, in order from object side, a first group Gr1 having negative refracting power, a second group Gr2 having positive refracting power, and a third group Gr3 having positive refracting power. An affocal system is substantially formed by the Gr1 and Gr2, and at the focusing from infinite object side to near object side, all the Gr1-Gr3 are moved on the object side and focused so that the air space between the Gr1 and Gr2 is slightly reduced, and the air space between the Gr2 and Gr3 is slightly increased.