A laser gas analyzer, comprising: a light emitter for emitting a laser light irradiated onto a gas to be measured; a light receiver for receiving a laser light which transmitted the gas to be measured; a plurality of optical-axis adjustment mechanisms (10b, 20b), one of which is provided in the light emitter and the other one of which is provided in the light receiver; a main display which is provided in one of the light emitter and the light receiver for displaying thereon a measured result acquired by receiving the laser light which transmitted the gas to be measured, wherein the main display is arranged to display thereon, as measured result, at least information which indicates a concentration of the gas to be measured and a transmittance of the laser light; a sub-display which is provided in the other one of the light emitter and the light receiver for displaying thereon a part of the measured result displayed on the main display, wherein the sub-display is arranged to display information indicating the transmittance of the laser light as a part of the measured result; and a calculation device which is provided in one of the light emitter and the light receiver for calculating the measured result using a light receiving signal which is acquired by receiving the laser light which transmitted the gas to be measured, wherein the calculation device is arranged for calculating, as measured result, the concentration of the gas to be measured and the transmittance of the laser light, wherein the calculation device is arranged to update the display content of the main display and of the sub-display for each calculation period of the calculation device, wherein, based on a signal from the calculation device, at least one of the main display and sub-display is arranged to vary for each calculation period of the calculation device at least a part of the display content to report the update, and wherein the plurality of optical-axis adjustment mechanisms (10b, 20b) can be adjusted such that the transmittance of the laser light is maximal. a light emitter for emitting a laser light irradiated onto a gas to be measured; a light receiver for receiving a laser light which transmitted the gas to be measured; a plurality of optical-axis adjustment mechanisms (10b, 20b), one of which is provided in the light emitter and the other one of which is provided in the light receiver; a main display which is provided in one of the light emitter and the light receiver for displaying thereon a measured result acquired by receiving the laser light which transmitted the gas to be measured, wherein the main display is arranged to display thereon, as measured result, at least information which indicates a concentration of the gas to be measured and a transmittance of the laser light; a sub-display which is provided in the other one of the light emitter and the light receiver for displaying thereon a part of the measured result displayed on the main display, wherein the sub-display is arranged to display information indicating the transmittance of the laser light as a part of the measured result; and a calculation device which is provided in one of the light emitter and the light receiver for calculating the measured result using a light receiving signal which is acquired by receiving the laser light which transmitted the gas to be measured, wherein the calculation device is arranged for calculating, as measured result, the concentration of the gas to be measured and the transmittance of the laser light, wherein the calculation device is arranged to update the display content of the main display and of the sub-display for each calculation period of the calculation device, wherein, based on a signal from the calculation device, at least one of the main display and sub-display is arranged to vary for each calculation period of the calculation device at least a part of the display content to report the update, and wherein the plurality of optical-axis adjustment mechanisms (10b, 20b) can be adjusted such that the transmittance of the laser light is maximal.