IPI2Win(MT) is an interactive geophysical program designed for 1D interpretation of magnetotelluric (MT) data along one observation profile. It is assumed that the user of the program is an experienced geophysicist, who aims at finding the result that yields both satisfactory data fit as well as the solution of the geological problem. A distinctive feature of the IPI2Win(MT) program is the focus on the geological result achieved by interactive , which differs it from other common programs of automatic 1D MT interpretation.