A method for analyzing a heat exchanger having a heat exchanger main body formed by a plurality of heat transfer tube groups, each of which is formed of a plurality of heat transfer tubes arranged side by side in an in-plane direction, being stacked in an out-of-plane direction intersecting the in-plane direction and an anti-vibration member provided between the heat transfer tube groups adjacent to each other to extend to intersect the heat transfer tubes, the method comprising: a structural model creation step of creating a structural model of the heat exchanger; a linear model creation step of creating a linear model in which a linear spring element in the out-of-plane direction is applied to all of the opposing portions of the structural model; and a primary response analysis step of performing response analysis in which a seismic wave is applied to the linear model to acquire a deformation amount of the linear model, a non-linear model creation step of creating a non-linear model in which a non-linear spring element in the out-of-plane direction, in which a load is not generated at the time of non-contact between the heat transfer tube and the anti-vibration member and a load is generated at the time of contact, is applied to each opposing portion between the heat transfer tube and the anti-vibration member in the out-of-plane direction in the structural model; and a load distribution acquisition step of performing analysis in which the load in the out-of-plane direction is applied to the non-linear model to acquire load distribution of the heat exchanger from a value of the load in each of the opposing portions, wherein in the load distribution acquisition step, a load is applied to the non-linear model such that a deformation amount of the non-linear model becomes a value corresponding to the deformation amount acquired in the primary response analysis step, and wherein the method for analyzing a heat exchanger further comprises: a linear gap model creation step of creating a linear gap model in which a linear spring element in the out-of-plane direction is applied to only the opposing portion in which the load is generated, out of the opposing portions of the structural model, according to the load distribution; and a seismic evaluation step of performing seismic evaluation by using the linear gap model. a structural model creation step of creating a structural model of the heat exchanger; a linear model creation step of creating a linear model in which a linear spring element in the out-of-plane direction is applied to all of the opposing portions of the structural model; and a primary response analysis step of performing response analysis in which a seismic wave is applied to the linear model to acquire a deformation amount of the linear model, a non-linear model creation step of creating a non-linear model in which a non-linear spring element in the out-of-plane direction, in which a load is not generated at the time of non-contact between the heat transfer tube and the anti-vibration member and a load is generated at the time of contact, is applied to each opposing portion between the heat transfer tube and the anti-vibration member in the out-of-plane direction in the structural model; and a load distribution acquisition step of performing analysis in which the load in the out-of-plane direction is applied to the non-linear model to acquire load distribution of the heat exchanger from a value of the load in each of the opposing portions, wherein in the load distribution acquisition step, a load is applied to the non-linear model such that a deformation amount of the non-linear model becomes a value corresponding to the deformation amount acquired in the primary response analysis step, and wherein the method for analyzing a heat exchanger further comprises: a linear gap model creation step of creating a linear gap model in which a linear spring element in the out-of-plane direction is applied to only the opposing portion in which the load is generated, out of the opposing portions of the structural model, according to the load distribution; and a seismic evaluation step of performing seismic evaluation by using the linear gap model. a linear gap model creation step of creating a linear gap model in which a linear spring element in the out-of-plane direction is applied to only the opposing portion in which the load is generated, out of the opposing portions of the structural model, according to the load distribution; and a seismic evaluation step of performing seismic evaluation by using the linear gap model.