An analysis method for analyzing deformation of a casting in a die casting process includes obtaining a first die frictional stress exerted by a first die on the casting in a mold opening step, and calculating deformation of the casting in the mold opening step using the first die frictional stress. A predetermined frictional coefficient function is selected from a plurality of frictional coefficient functions based on casting conditions and lubrication conditions. A frictional coefficient at each portion of the casting is output by inputting a temperature of a contact surface between the casting and the first die and a contact surface pressure therebetween into the selected predetermined frictional coefficient function. The first die frictional stress acting on each portion of the casting is obtained by multiplying the contact surface pressure and the frictional coefficient.