There is provided a sample analyzing apparatus capable of simply and rapidly carrying out each step of electrophoresis, transfer and detection to analyze a substance, such as a biosubstance, in a sample. By sticking an upper plate member 14 to a lower plate member 12 having a fine groove 12a, an electrophoresis passage 13 is formed in the apparatus. A pair of separating electrodes 18 and 20 are provided for moving a substance, such as a biosubstance, along the electrophoresis passage 13 by electrophoresis, and a pair of transferring electrodes 16 and 22 are arranged in the electrophoresis passage 13 for transferring the substance to a capturing material 24 by electrophoresis. After a voltage is applied between the separating electrodes 18 and 20 to carry out electrophoresis, a voltage is applied between the transferring electrodes 16 and 20 to change the direction of electrophoresis to carry out transfer to the capturing material 24, and thereafter, a detecting reaction is allowed in the electrophoresis passage 13 to analyze the substance.