The present invention provides an isoquinoline-6-sulfonamide derivative that is useful as a novel pharmaceutical agent. The present invention provides an isoquinoline-6-sulfonamide derivative represented by Formula (1), a salt thereof, or a solvate of the derivative or the salt: wherein X and Y each independently represent a direct bond, NH, CH═CH, O, or S； R1 and R2 each independently represent a hydrogen atom, a halogen atom, a cyano group, an alkyl group, or the like； R3 and R4 each independently represent a hydrogen atom, an alkyl group, or the like, or R3 and R4 together form an alkylene group or an alkenylene group, which may be bridged between two carbon atoms to an arbitrary position； and l, m, and n represent an integer number of 1 to 4.
