Inhaler for dry powder, having a substantially cylindrical body (310) that defines a dispersion chamber (311), said body (310) having on its cylindrical wall a mouthpiece (330) that defines a dispensing orifice (331), said body (310) being provided, at its first axial end part, with a knurled wheel (370) mounted rotatably on said body (310), said knurled wheel (370) having a loading aperture (371) for receiving a capsule (10) containing a dose of dry powder, said body (310) being provided, at its second axial end part, with a stopper (360) mounted removably on said body (310), said body (310) having at least one opening profile (312, 313) designed to open a capsule (10), which has been inserted into said loading aperture (371), when said knurled wheel (370) is moved in rotation with respect to said body (310).