This crane position determination device is to be mounted on a mobile crane, said crane position determination device comprising: an input unit that receives input of the working conditions of crane work; a determination unit that has a learning model and determines the placement position of the mobile crane on the basis of output from the learning model; and a notification unit that provides notification of the placement position of the mobile crane, wherein on the basis of a reward function including at least one evaluation function pertaining to the crane work, the learning model learns to output information pertaining to the optimum placement position of the mobile crane with respect to the working conditions.