To estimate the power transmission state of a friction factor or the like without causing a slip actually in the space between a metal belt and a pulley of a metal belt type continuously variable transmission.

A vector sum of friction factors μTON and μRDN of a driven pulley is assumed as 0.1, a friction factor μROR of a drive pulley is assemed as 0, and two friction factors μSDR and μSDN of the pulley at a side being small in a winding diameter are assumed as 0.1 as well. In addition, each speed ratio of both these pulleys, revolution NIN, of the drive pulley, input torque TIN of the drive pulley and axial thrust QPN of the driven pulley are all measured, and these values are substituted into a relational expression for equilibrium of force at every part of a metal belt type continuously variable transmission, whereby those of axial thrust QDR of the drive pulley, pushing forces E1 and E2 between blocks, intersahft force FS, ring tensions T1 and T2, three friction factors μTDR, μTDN and μRDN, and two friction factors MSDR and MSDN at the side being large in the winding diameter are all calculable.