A perimeter capable of acquiring a threshold value corresponding to a response result of an examinee to a stimulus presented with various brightness, for a first number of measurement points set across an entire measurement visual field of the ocular fundus of a subject eye, comprising: a memory; a visual field measurer configured to measure the visual field of the examinee's eye to obtain the minimum values of brightness of the stimuli to which the examinee can respond, thresholds, regarding a plurality of measurement points, a map image creator configured to compute a pattern deviation of the threshold value regarding each measurement point, wherein the pattern deviation is the difference between the threshold actually measured and an estimated threshold read out of the memory, a point extractor that obtains a probability P value representing the obtained pattern deviation for each measurement point as a probability variable, and generates a probability map image of a pattern deviation probability plot indicating the measurement points for the respective P values; characterized in that the point extractor further selects abnormal measurement point groups to be used as subsequent measurement points, until a prescribed number of points which is smaller than the first number, the abnormal measurement point groups has measurement points having a P value that is a first prescribed value (e.g. P < 5 %) or lower and being adjacent to one another in the probability map image and at least one measurement point of the abnormal measurement point groups has the P value that is a second prescribed value (e.g. P < 1%) or lower, that is smaller than the first prescribed value (e.g. P < 5 %), and; a memory that stores the subsequent measurement points selected through the point extractor, wherein the selection of the subsequent measurement points through the point extractor is controlled in such a way that the measurement points are selected from ones comprising the abnormal measurement point groups having a higher pattern deviation. a memory; a visual field measurer configured to measure the visual field of the examinee's eye to obtain the minimum values of brightness of the stimuli to which the examinee can respond, thresholds, regarding a plurality of measurement points, a map image creator configured to compute a pattern deviation of the threshold value regarding each measurement point, wherein the pattern deviation is the difference between the threshold actually measured and an estimated threshold read out of the memory, a point extractor that obtains a probability P value representing the obtained pattern deviation for each measurement point as a probability variable, and generates a probability map image of a pattern deviation probability plot indicating the measurement points for the respective P values; characterized in that the point extractor further selects abnormal measurement point groups to be used as subsequent measurement points, until a prescribed number of points which is smaller than the first number, the abnormal measurement point groups has measurement points having a P value that is a first prescribed value (e.g. P < 5 %) or lower and being adjacent to one another in the probability map image and at least one measurement point of the abnormal measurement point groups has the P value that is a second prescribed value (e.g. P < 1%) or lower, that is smaller than the first prescribed value (e.g. P < 5 %), and; a memory that stores the subsequent measurement points selected through the point extractor, wherein the selection of the subsequent measurement points through the point extractor is controlled in such a way that the measurement points are selected from ones comprising the abnormal measurement point groups having a higher pattern deviation.