A dynamometer for measuring load of a rotary shaft to be tested, the dynamometer comprising: a dynamometer shaft connected to the rotary shaft to be tested; a casing part having a through hole through which the dynamometer shaft passes, being provided in a circumferential surface of the dynamometer shaft (1 100), and having a water supply chamber and a drain chamber therein; and a stator part including a first stator and a second stator provided in the casing part to be spaced apart from each other, both of which provide a space for forming a toroidal chamber on the circumferential surface of the dynamometer shaft, the stator part being formed with a supply nozzle (1312a,1322a) through which fluid of the water supply chamber is supplied into the toroidal chamber; characterized in that the dynamometer further comprises: a toroidal chamber partitioning part positioned between the first stator and the second stator and partitioning the toroidal chamber into a first toroidal chamber and a second toroidal chamber, both of which are positioned to be spaced apart from each other, wherein the toroidal chamber partitioning part comprises a runner mounted on the circumferential surface of the dynamometer shaft and a guide ring having one end fixed to the casing part and the other end protruding into the toroidal chamber, the runner configured to rotate together upon rotation of the dynamometer shaft, and the guide ring configured to guide fluid in rotation in the first toroidal chamber and the second toroidal chamber to the drain chamber upon rotation of the runner, the guide ring forming a drain slot in between the stator part, through which the fluid is discharged from the first toroidal chamber and the second toroidal chamber to the drain chamber; and flow adjusting parts provided in the first toroidal chamber and the second toroidal chamber respectively, adjusting flow rates of the fluid circulating in the first toroidal chamber and the second toroidal chamber. a dynamometer shaft connected to the rotary shaft to be tested; a casing part having a through hole through which the dynamometer shaft passes, being provided in a circumferential surface of the dynamometer shaft (1 100), and having a water supply chamber and a drain chamber therein; and a stator part including a first stator and a second stator provided in the casing part to be spaced apart from each other, both of which provide a space for forming a toroidal chamber on the circumferential surface of the dynamometer shaft, the stator part being formed with a supply nozzle (1312a,1322a) through which fluid of the water supply chamber is supplied into the toroidal chamber; characterized in that the dynamometer further comprises: a toroidal chamber partitioning part positioned between the first stator and the second stator and partitioning the toroidal chamber into a first toroidal chamber and a second toroidal chamber, both of which are positioned to be spaced apart from each other, wherein the toroidal chamber partitioning part comprises a runner mounted on the circumferential surface of the dynamometer shaft and a guide ring having one end fixed to the casing part and the other end protruding into the toroidal chamber, the runner configured to rotate together upon rotation of the dynamometer shaft, and the guide ring configured to guide fluid in rotation in the first toroidal chamber and the second toroidal chamber to the drain chamber upon rotation of the runner, the guide ring forming a drain slot in between the stator part, through which the fluid is discharged from the first toroidal chamber and the second toroidal chamber to the drain chamber; and flow adjusting parts provided in the first toroidal chamber and the second toroidal chamber respectively, adjusting flow rates of the fluid circulating in the first toroidal chamber and the second toroidal chamber. a toroidal chamber partitioning part positioned between the first stator and the second stator and partitioning the toroidal chamber into a first toroidal chamber and a second toroidal chamber, both of which are positioned to be spaced apart from each other, wherein the toroidal chamber partitioning part comprises a runner mounted on the circumferential surface of the dynamometer shaft and a guide ring having one end fixed to the casing part and the other end protruding into the toroidal chamber, the runner configured to rotate together upon rotation of the dynamometer shaft, and the guide ring configured to guide fluid in rotation in the first toroidal chamber and the second toroidal chamber to the drain chamber upon rotation of the runner, the guide ring forming a drain slot in between the stator part, through which the fluid is discharged from the first toroidal chamber and the second toroidal chamber to the drain chamber; and flow adjusting parts provided in the first toroidal chamber and the second toroidal chamber respectively, adjusting flow rates of the fluid circulating in the first toroidal chamber and the second toroidal chamber.