An eye movement measuring apparatus comprising: a light source; an interference light generator (162, 163, 164, 174) adapted to split a light output from said light source into a signal light directed toward an eye to be measured and a reference light directed toward a reference object, and also adapted to generate an interference light by overlaying the signal light propagating to and from said eye to be measured and the reference light propagating to and from said reference object; a detector adapted to output a detection signal upon receipt of said generated interference light; a scanner (141, 141A, 141B) adapted to scan an incident position of said signal light with respect to said eye to be measured in a given main scanning direction and in a sub-scanning direction perpendicular to the main scanning direction respectively; and an image forming part (1A, 150, 220) adapted to form an image in a depth direction of said eye to be measured at said incident position on the basis of said detection signal based on the interference light formed by said signal light propagating to and from the incident position and said reference light and adapted to form two or more tomographic images along said main scanning directions at different positions in said sub-scanning direction by forming the tomographic image along said main scanning direction based on said image at each of said formed incident positions, for each of a plurality of said incident positions along said main scanning direction, so as to form a 3-dimensinal image; characterized in that: said scanner is adapted to scan said signal light in a crossing direction crossing with said main scanning direction from a scan end position on the last scanning line (Rm) to a scan start position on the first scanning line, said eye movement measuring apparatus further comprises an image analysis part adapted to form a tomographic image for reference along said crossing direction and to determine eye movement of the eye to be measured by comparing said tomographic image for reference with a tomographic image obtained as cross section of said 3-dimensional image along said crossing direction. a light source; an interference light generator (162, 163, 164, 174) adapted to split a light output from said light source into a signal light directed toward an eye to be measured and a reference light directed toward a reference object, and also adapted to generate an interference light by overlaying the signal light propagating to and from said eye to be measured and the reference light propagating to and from said reference object; a detector adapted to output a detection signal upon receipt of said generated interference light; a scanner (141, 141A, 141B) adapted to scan an incident position of said signal light with respect to said eye to be measured in a given main scanning direction and in a sub-scanning direction perpendicular to the main scanning direction respectively; and an image forming part (1A, 150, 220) adapted to form an image in a depth direction of said eye to be measured at said incident position on the basis of said detection signal based on the interference light formed by said signal light propagating to and from the incident position and said reference light and adapted to form two or more tomographic images along said main scanning directions at different positions in said sub-scanning direction by forming the tomographic image along said main scanning direction based on said image at each of said formed incident positions, for each of a plurality of said incident positions along said main scanning direction, so as to form a 3-dimensinal image; characterized in that: said scanner is adapted to scan said signal light in a crossing direction crossing with said main scanning direction from a scan end position on the last scanning line (Rm) to a scan start position on the first scanning line, said eye movement measuring apparatus further comprises an image analysis part adapted to form a tomographic image for reference along said crossing direction and to determine eye movement of the eye to be measured by comparing said tomographic image for reference with a tomographic image obtained as cross section of said 3-dimensional image along said crossing direction. said scanner is adapted to scan said signal light in a crossing direction crossing with said main scanning direction from a scan end position on the last scanning line (Rm) to a scan start position on the first scanning line, said eye movement measuring apparatus further comprises an image analysis part adapted to form a tomographic image for reference along said crossing direction and to determine eye movement of the eye to be measured by comparing said tomographic image for reference with a tomographic image obtained as cross section of said 3-dimensional image along said crossing direction.