A reliable detection of optically detecting the type of recording media is achieved. A part of a support member for supporting an optical sensor is pushed against the surface of a sheet by a spring so as to maintain the gap between the sensor and the sheet surface. With this arrangement, a recording apparatus which is free from wrong detection is achieved regardless of a gap-varying factor, that is, the remaining amount of sheets. Also, by arranging a part of a light-shielding hood so as to abut against the sheet, wrong detection due to disturbance light can be prevented.