An endoscope system is able to stably obtain an image free from speckle interference. A captured image including a first basic color component B on which a speckle noise of a laser beam is superimposed and a second basic color component G not including the speckle noise. A speckle noise component Bs is extracted based on difference information between the first basic color component B and the second basic color component G Based on the extracted speckle noise component Bs, the speckle noise component Bs is removed from the first basic color component B, so as to obtain a good observation image free from the speckle noise.