An electrophoresis apparatus (1, 80, 140, 150) that applies voltage from electrodes (21, 22, 86, 87) that are provided in a capillary flow channel (47, 99) and causes component separation by performing electrophoresis on a specimen that is injected into the capillary flow channel (47,99), the electrophoresis apparatus comprising: a physical quantity acquisition unit that, with migration solution and specimen injected inside the capillary flow channel (47, 99), is configured to acquire an electrical current that occurs in the capillary flow channel (47, 99) at a specified time when voltage is being applied to the electrodes (21, 22, 86, 87); a physical quantity determination unit that is configured to determine whether or not the electrical current is within a specified range; a memory unit that is configured to store the electrical current acquired by the physical quantity acquisition unit; and a voltage change unit that is configured to change the size of the voltage that is applied to the electrodes (21, 22, 86, 87); wherein the physical quantity acquisition unit is configured to acquire an electrical current that occurs in the capillary flow channel (47, 99) while the voltage is being applied to the electrodes; and wherein the physical quantity determination unit is configured to determine whether or not the absolute value of the electrical current exceeds a pre-set threshold value, or whether or not the difference that is calculated between the electrical current and an electrical current that was stored in the memory unit in the past based on the threshold value exceeds a specified value; characterized in that: when the physical quantity determination unit determines that the difference exceeds the specified value, the voltage change unit is configured to calculate a correction value for the voltage applied to the electrodes (21, 22, 86, 87) based on the electrical current whose difference from the electrical current that was stored in the memory unit in the past does not exceed the specified value, or based on a preset target value for the electrical current, and to change the size of the voltage applied to the electrodes (21, 22, 86, 87) to the correction value, and further characterized by: a cleaning determination unit that, when the physical quantity determination unit determines that the absolute value exceeds the pre-set threshold value, is configured to output a cleaning signal for cleaning the capillary flow channel (47, 99). a physical quantity acquisition unit that, with migration solution and specimen injected inside the capillary flow channel (47, 99), is configured to acquire an electrical current that occurs in the capillary flow channel (47, 99) at a specified time when voltage is being applied to the electrodes (21, 22, 86, 87); a physical quantity determination unit that is configured to determine whether or not the electrical current is within a specified range; a memory unit that is configured to store the electrical current acquired by the physical quantity acquisition unit; and a voltage change unit that is configured to change the size of the voltage that is applied to the electrodes (21, 22, 86, 87); wherein the physical quantity acquisition unit is configured to acquire an electrical current that occurs in the capillary flow channel (47, 99) while the voltage is being applied to the electrodes; and wherein the physical quantity determination unit is configured to determine whether or not the absolute value of the electrical current exceeds a pre-set threshold value, or whether or not the difference that is calculated between the electrical current and an electrical current that was stored in the memory unit in the past based on the threshold value exceeds a specified value; characterized in that: when the physical quantity determination unit determines that the difference exceeds the specified value, the voltage change unit is configured to calculate a correction value for the voltage applied to the electrodes (21, 22, 86, 87) based on the electrical current whose difference from the electrical current that was stored in the memory unit in the past does not exceed the specified value, or based on a preset target value for the electrical current, and to change the size of the voltage applied to the electrodes (21, 22, 86, 87) to the correction value, and further characterized by: a cleaning determination unit that, when the physical quantity determination unit determines that the absolute value exceeds the pre-set threshold value, is configured to output a cleaning signal for cleaning the capillary flow channel (47, 99). when the physical quantity determination unit determines that the difference exceeds the specified value, the voltage change unit is configured to calculate a correction value for the voltage applied to the electrodes (21, 22, 86, 87) based on the electrical current whose difference from the electrical current that was stored in the memory unit in the past does not exceed the specified value, or based on a preset target value for the electrical current, and to change the size of the voltage applied to the electrodes (21, 22, 86, 87) to the correction value, and further characterized by: a cleaning determination unit that, when the physical quantity determination unit determines that the absolute value exceeds the pre-set threshold value, is configured to output a cleaning signal for cleaning the capillary flow channel (47, 99).