The creep effect in relationship with the research of pneumatic artificial muscles represents a dynamic phenomenon characterized by slow changes in muscle displacement caused by the material's elasticity. However, the temperature of the environment in which the muscle works affects the temperature of the muscle. It also affects the creep effect itself; as a result, the process of identifying hysteresis models of muscle becomes difficult. The article contains a description and implementation of a measuring apparatus designed to measure the temperature dependence of the creep effect of fluid muscles. The apparatus was designed and constructed at the authors' workplace to analyze the creep effect and evaluate its impact on the accuracy of experimental models describing the dynamics of the drive.