Bonding device and bonding method

The invention provides a bonding device and a bonding method, which can improve alignment precision before bonding. The bonding apparatus bonds a first substrate having a first alignment mark and a second substrate having a second alignment mark. When the first imaging unit captures an image of the second alignment mark, the first irradiation unit irradiates white light to an imaging region of the first imaging unit. The second irradiation unit irradiates white light to an imaging region of the second imaging unit when the second imaging unit captures an image of the first alignment mark. The control unit detects the positions of the first alignment mark and the second alignment mark by processing the images captured by the first imaging unit and the second imaging unit. The control unit corrects the position of the detected first alignment mark on the basis of the relationship between the wavelength and intensity of the reflected light reflected by the first substrate. The control unit controls the moving un