A laser radar device, comprising: a light source that outputs transmission light to a target; an transmission optical system that makes the transmission light output by the light source at a predetermined beam spread angle; a light-receiving element array that receives scattered light from the target with respect to the transmission light made at the predetermined beam spread angle by the transmission optical system and that converts the resultant to an electric signal; an electric circuit array that detects a reception intensity and a reception time from the electric signal converted by the light-receiving element array; a measuring unit that measures a range to the target or a three-dimensional shape of the target on the basis of the reception time detected by the electric circuit array; a determination unit that determines whether to perform a shift from a range finding mode that measures the range to the target to an imaging mode that measures a three-dimensional shape of the target on the basis of the reception intensity and the reception time detected by the electric circuit array; and a controller that changes the beam spread angle by the transmission optical system on the basis of a determination result by the determination unit, characterized in that the determination unit performs the determination by comparing a reception S/N ratio determined based on the reception intensity and a previously-known reception noise level with a predetermined threshold value, wherein when the range to the target shifts from a long range to a short range, the controller changes the beam spread angle by the transmission optical system on the basis of the determination result by the determination 92) unit, and also the measuring unit shifts from the range finding mode to the imaging mode a light source that outputs transmission light to a target; an transmission optical system that makes the transmission light output by the light source at a predetermined beam spread angle; a light-receiving element array that receives scattered light from the target with respect to the transmission light made at the predetermined beam spread angle by the transmission optical system and that converts the resultant to an electric signal; an electric circuit array that detects a reception intensity and a reception time from the electric signal converted by the light-receiving element array; a measuring unit that measures a range to the target or a three-dimensional shape of the target on the basis of the reception time detected by the electric circuit array; a determination unit that determines whether to perform a shift from a range finding mode that measures the range to the target to an imaging mode that measures a three-dimensional shape of the target on the basis of the reception intensity and the reception time detected by the electric circuit array; and a controller that changes the beam spread angle by the transmission optical system on the basis of a determination result by the determination unit, characterized in that the determination unit performs the determination by comparing a reception S/N ratio determined based on the reception intensity and a previously-known reception noise level with a predetermined threshold value, wherein when the range to the target shifts from a long range to a short range, the controller changes the beam spread angle by the transmission optical system on the basis of the determination result by the determination 92) unit, and also the measuring unit shifts from the range finding mode to the imaging mode