PURPOSE: To eliminate a feeling of uneasiness that part of a human body may touch a slide panel by arranging photo-sensor units at the opening section of a roof panel, and operating a control circuit not to close the slide panel when an obstacle exists.

CONSTITUTION: An openable slide panel 2 is provided on the roof panel 1 of an automobile, sensor units 5R and 5L constituted of light emitting elements 51 and 53 and light receiving elements 52 and 54 respectively are arranged, and optical paths 100 and 200 are formed between both units. When the slide panel 2 is to be closed, signals from light receiving elements 52 and 54 are monitored by a microcomputer to confirm whether an obstacle exists in the opening section 6. A control circuit is operated not to close the slide panel 2 when the obstacle 7 exists. A driving mechanism is automatically stopped before part of a human body touches the slide panel 2, and a feeling of uneasiness or uncomfortableness can be eliminated.