A braking device for an automatic winding type screen device that stably brakes the automatic winding of a screen regardless of the temperature. The braking device comprises: a housing that is provided inside a winding shaft so as to be able to turn with the winding shaft to wind up a screen; a sleeve that is inserted into the housing and is mounted to a bracket so as not to be able to turn; and a mobile element that can rotate with the housing. A first spring and a second spring are provided on the outer side of the sleeve so as to have the mobile element therebetween. The mobile element twists forward on the sleeve along with rotation of the housing, and biasing forces of the first spring and the second spring that expand and contact with the forward twist of the mobile element brakes the rotation of the winding shaft.