The invention provides an elevator car monitoring device and a monitoring method, which can be used for the leveling control of the elevator card in a high-precision manner by using the simple structure without requiring the arrangement of a plurality of shielding boards and a plurality of corresponding detection parts, which are disposed on the same floor. The elevator car monitoring device comprises a unit (16) used for acquiring elevator car position information by using an elevator car position detection device (14) of an coder (10) used for a speed regulator, a unit (16)used for acquiring floor height value information of every floor, a unit (18) used for detecting a jump between an elevator car floor and an elevator hall floor according to the elevator car position information and the floor height value information, a unit (17) used for transmitting a leveling control correction signal to an elevator control device 13, and a unit (19) used for storing a determining value. When the calculated jump exceeds the determining value, the leveling control correction signal can be transmitted to the elevator control device (13).