To provide a technique for deciding the mechanical characteristics of an insulating film material by using a parameter related to the mechanical characteristics of an insulating film material except elastic modulus and hardness which shows a relation to a failure generated upon employing a semiconductor device.

The mechanical characteristics deciding method of an insulating thin film material employed for a semiconductor device comprises an indenter pushing energy obtaining process (A102, S104), wherein an indenter is pushed to obtain the indenter pushing energy based on a load from no-load to the maximum load and the amount of displacement, and an elastic recovery energy obtaining process (A106, S108) wherein an elastic recovery energy is obtained based on respective loads and amounts of displacement upon releasing the pushed indenter from the maximum load to no-load. The mechanical characteristic of the insulating material thin film is decided (S112) by a value obtained by dividing a difference between the indenter pushing energy and the elastic recovery energy by the indenter pushing energy.