A steel strip notching method comprising forming a notch at an end portion of a joint in a strip width direction, the joint being formed by joining a trailing end of a preceding steel strip to a leading end of a succeeding steel strip, and removing at least part of a region of the notch through grinding, wherein at least the part of the region of the notch to be removed by the grinding is removed by grinding which involves; cutting the region with a rotary grinding tool by feeding the rotary grinding tool in the strip width direction, feeding the rotary grinding tool in a strip vertical direction at a feed rate within a predetermined range with respect to a feed rate of the rotary grinding tool in the strip width direction, giving a predetermined feed amount in a strip longitudinal direction while feeding the rotary grinding tool by a predetermined feed amount in the strip width direction simultaneously with feeding the rotary grinding tool in the strip vertical direction, and cutting the region while oscillating the rotary grinding tool in the strip longitudinal direction, wherein the rotary grinding tool is a rotary burr, and the rotary burr is fed in the strip vertical direction at a feed rate 0.3 to 10.0 times a feed rate of the rotary burr in the strip width direction, and wherein a feed amount greater than or equal to 5.0% of a diameter of the rotary burr is given in the strip longitudinal direction while the rotary burr is fed in the strip width direction by a predetermined feed amount less than or equal to 1.0% of the diameter of the rotary burr, and a travel of the rotary burr in the strip longitudinal direction turns before the feed amount of the rotary burr in the strip width direction exceeds 1.0% of the diameter of the rotary burr, and the feed amount in the strip longitudinal direction from a turning point to a next turning point is greater than or equal to 5.0% of the diameter of the rotary burr. wherein at least the part of the region of the notch to be removed by the grinding is removed by grinding which involves; cutting the region with a rotary grinding tool by feeding the rotary grinding tool in the strip width direction, feeding the rotary grinding tool in a strip vertical direction at a feed rate within a predetermined range with respect to a feed rate of the rotary grinding tool in the strip width direction, giving a predetermined feed amount in a strip longitudinal direction while feeding the rotary grinding tool by a predetermined feed amount in the strip width direction simultaneously with feeding the rotary grinding tool in the strip vertical direction, and cutting the region while oscillating the rotary grinding tool in the strip longitudinal direction, wherein the rotary grinding tool is a rotary burr, and the rotary burr is fed in the strip vertical direction at a feed rate 0.3 to 10.0 times a feed rate of the rotary burr in the strip width direction, and wherein a feed amount greater than or equal to 5.0% of a diameter of the rotary burr is given in the strip longitudinal direction while the rotary burr is fed in the strip width direction by a predetermined feed amount less than or equal to 1.0% of the diameter of the rotary burr, and a travel of the rotary burr in the strip longitudinal direction turns before the feed amount of the rotary burr in the strip width direction exceeds 1.0% of the diameter of the rotary burr, and the feed amount in the strip longitudinal direction from a turning point to a next turning point is greater than or equal to 5.0% of the diameter of the rotary burr.