A respiratory mask includes a single-piece first cushion ring defining an airflow channel and having a front cover-engaging end portion and a rear abutment end portion adapted to abut against a user's face below the forehead, a cover shell having a cover plate engaged to the front cover-engaging end portion and provided with a connecting hole that is adapted to be connected to an air supply source, a resilient forehead support connected to a top end of the front cover-engaging end portion and bendable toward the rear abutment end portion, a resilient forehead abutment body connected to a top end of and supported by the resilient forehead support and including a second cushion ring adapted to abut against the forehead of the user, and an adjustable head strap unit connected to the first cover shell and the resilient forehead abutment body.