The light source device 3 includes a lighting time measuring unit (steps S3, 4, 6, and 7) that measures the lighting time of each LED, a junction temperature calculating unit (steps S5 and 8) that calculates the junction temperature of each LED, A light quantity deterioration characteristic storage unit that stores light quantity deterioration characteristics based on the junction temperature of the LED, a light source drive characteristic storage unit that stores characteristics of power and light quantity for driving each LED, a measured lighting time, and a calculated junction Based on the temperature and the light amount deterioration characteristic stored in the light amount deterioration characteristic storage unit, the deteriorated light amount calculation unit (steps S12 and S14) that calculates the deteriorated light amount, the deteriorated light amount calculated by the deteriorated light amount calculation unit, and the light source And a light source power control unit (steps S12 and S14) for controlling power for driving the light source based on the characteristics stored in the drive characteristic storage unit.光源装置３は、各ＬＥＤの点灯時間を計測する点灯時間計測部（ステップＳ３，４，６，７）と、各ＬＥＤのジャンクション温度を算定するジャンクション温度算定部（ステップＳ５，８）と、各ＬＥＤのジャンクション温度に基づく光量劣化特性を記憶する光量劣化特性記憶部と、各ＬＥＤを駆動する電力と光量の特性を記憶する光源駆動特性記憶部と、計測された点灯時間と、算定されたジャンクション温度と、光量劣化特性記憶部に記憶されている光量劣化特性とに基づき、劣化光量を演算する劣化光量演算部（ステップＳ１２，１４）と、劣化光量演算部により演算された劣化光量と、光源駆動特性記憶部に記憶されている特性とに基づき、光源を駆動する電力を制御する光源電力制御部（ステップＳ１２，１４）とを有する。
