According to one embodiment of the present invention, a catheter for multi-electrode mapping and ablation can simultaneously remove lesion parts existing in a heart tissue by inserting a distal part into the human body. The catheter includes: a catheter conduit having a hollow inner space in which a guide member is installed； a hand manipulation part connected to a guide member at a proximal part of the catheter conduit to manipulate the degree of curve of a distal part of the catheter conduit； a plurality of mapping electrodes arranged in a row in a direction from a terminal end of the distal part to the proximal part while being spaced apart from each other, surrounding an outer peripheral surface of the distal part of the catheter conduit, and making surface-contact with a heart tissue when being inserted into the heart tissue of the catheter conduit to map a plurality of lesion parts； a plurality of ablation electrodes spaced apart from the mapping electrodes, arranged in a row in a direction from the distal part to the proximal part while being spaced apart from each other, surrounding the outer peripheral surface of the distal part of the catheter conduit, and removing the lesion parts as current is applied thereto； a plurality of liquid discharge holes formed in each outer peripheral surface of each ablation electrode； a liquid supply part having a liquid supply tube with one end connected to the liquid discharge holes in the catheter conduit； and a current applying unit including a current applying connector connected to the hand manipulation part at a position opposite to the catheter conduit, a plurality of mapping wires having one end connected to each mapping electrode in the catheter conduit and the other end connected to the current applying connector to supply mapping current to the mapping electrodes, and a plurality of ablation wires having one end connected to each ablation electrode in the catheter conduit and the other end connected to the curren
