To provide an operator discrimination apparatus and an operator discrimination method for accurately extracting approximate straight lines representing an arm of the operator and identify the operator by the direction of the approximate straight lines.

A differentiation part 33 of the operator discrimination apparatus 3 differentiates image data to create an x-axial differential image and a y-axial differential image. A calculation part 34 sets a first polar coordinate system having the coordinate origin at the center of a switch part 41, and calculates an angular differentiation and a radius directional differentiation according to the x-axial differential image and y-axial differential image. A binary image creation part 35 creates a binary image according to the angular differentiation and radius directional differentiation. An extraction part 36 extracts first and second straight lines 22 and 23 based on the binary image to detect an elbow center 24, and then repeats the processing to extract third and fourth straight lines 25 and 26. A determination part 37 identifies an operator by the direction of the third and fourth straight lines 25 and 26.