A laser excitation fluorescent microscope, comprising: a laser light source part radiating at least two types of excitation lights having different wavelengths; a light collecting part collecting the two types of excitation lights radiated by the laser light source part on a sample; a high functional dichroic mirror, disposed between the laser light source part and the light collecting part, reflecting the two types of excitation lights radiated by the laser light source part to make the excitation lights incident on the light collecting part, and transmitting two types of fluorescence generated at the sample in accordance with the two types of excitation lights; and a detecting part adapted to detect the two types of fluorescence transmitted through the dichroic mirror, wherein an incident angle θ of the excitation lights and the fluorescence to the dichroic mirror is smaller than 25°, and a wavelength characteristic curve of the dichroic mirror has a first reflecting band covering a wavelength of one of the two types of excitation lights, a first transmitting band covering a wavelength of fluorescence generated in accordance with the one of the two types of excitation lights, a second reflecting band covering a wavelength of the other one of the two types of excitation lights, and a second transmitting band covering a wavelength of fluorescence generated in accordance with the other one of the two types of excitation lights, in which the first reflecting band, the first transmitting band, the second reflecting band and the second transmitting band are in order from a short wavelength side, a wavelength width T 1 of the first transmitting band and a wavelength width T 2 of the second transmitting band are each 25 nm or more, a transmittance in each of the first transmitting band and the second transmitting band is 95% or more, a reflectivity in each of the first reflecting band and the second reflecting band is 95% or more, and a rising width A 1 from the first reflecting band to the first transmitting band and a rising width A 2 from the second reflecting band to the second transmitting band are each 6 nm or less. a laser light source part radiating at least two types of excitation lights having different wavelengths; a light collecting part collecting the two types of excitation lights radiated by the laser light source part on a sample; a high functional dichroic mirror, disposed between the laser light source part and the light collecting part, reflecting the two types of excitation lights radiated by the laser light source part to make the excitation lights incident on the light collecting part, and transmitting two types of fluorescence generated at the sample in accordance with the two types of excitation lights; and a detecting part adapted to detect the two types of fluorescence transmitted through the dichroic mirror, wherein an incident angle θ of the excitation lights and the fluorescence to the dichroic mirror is smaller than 25°, and a wavelength characteristic curve of the dichroic mirror has a first reflecting band covering a wavelength of one of the two types of excitation lights, a first transmitting band covering a wavelength of fluorescence generated in accordance with the one of the two types of excitation lights, a second reflecting band covering a wavelength of the other one of the two types of excitation lights, and a second transmitting band covering a wavelength of fluorescence generated in accordance with the other one of the two types of excitation lights, in which the first reflecting band, the first transmitting band, the second reflecting band and the second transmitting band are in order from a short wavelength side, a wavelength width T 1 of the first transmitting band and a wavelength width T 2 of the second transmitting band are each 25 nm or more, a transmittance in each of the first transmitting band and the second transmitting band is 95% or more, a reflectivity in each of the first reflecting band and the second reflecting band is 95% or more, and a rising width A 1 from the first reflecting band to the first transmitting band and a rising width A 2 from the second reflecting band to the second transmitting band are each 6 nm or less.