Structure stress estimation method

Provided is a stress estimation method that makes it possible to estimate the stress on a structure easily and with a high degree of accuracy. A stress estimation method according to an embodiment is provided with an attachment step for attaching, to the surface of a structure (10) including a metal member, a piezoelectric element (PE) for detecting elastic waves (AE) emitted when an inclusion in the metal member breaks; a step for applying pressure to the structure (10) to which the piezoelectric element (PE) has been attached; a step for specifying a reference pressure that was applied to the structure (10) when the piezoelectric element (PE) detected elastic waves; and a stress estimation step for determining an estimated stress on the structure (10) when a prescribed pressure is applied to the structure on the basis of the reference pressure and a reference stress that is the stress that was on the metal member when the inclusion broke.