The present invention relates to a dry powder inhaler device comprising a body having a guide surface formed on an inner surface thereof, a trigger having a socket with a shape complementing the guide surface, and a spring, characterized by comprising at least one retaining element (8) positioned on the inner surface (1) of the body diagonally across the spring (6) to enable the trigger (5) to perform a stable axial displacement and a mechanism check or quality control to be made as one of the parts of the device (7) body is not closed or assembled yet.