A method of manufacturing a magneto-sensitive wire for a magnetic impedance sensor capable of high-accuracy measurement, the magneto-sensitive wire comprising an amorphous wire for detecting magnetism, the magnetic impedance sensor having the magneto-sensitive wire and a detection coil around the magneto-sensitive wire, the magnetic impedance sensor being configured to apply a pulse current to the magneto-sensitive wire and detect a voltage generated in the detection coil thereby capable of measuring strength of a magnetic field, the voltage having magnitude in response to strength of an external magnetic field, the method comprising: performing an in-rotating liquid spinning method to manufacture the amorphous wire; and performing removal treatment by immersion in an acidic liquid, characterized in that: the method further comprising, after the in-rotating liquid spinning method, a subsequent wire drawing process to manufacture the amorphous wire, the removal treatment being performed for a process-affected residual layer generated at a surface and near the surface due to finishing by the wire drawing, the removal treatment being performed under a condition in which a wire diameter reduction rate with respect to a wire diameter before the removal treatment is 0.5-30%, a rate of the removal treatment for the process-affected residual layer is 10 micrometers per minute or less, the temperature of the acidic liquid being 10 to 60 degrees Celsius, and an amount of removal depending on a reduction rate of the cross-sectional area of the amorphous wire during the drawing process. the magneto-sensitive wire comprising an amorphous wire for detecting magnetism, the magnetic impedance sensor having the magneto-sensitive wire and a detection coil around the magneto-sensitive wire, the magnetic impedance sensor being configured to apply a pulse current to the magneto-sensitive wire and detect a voltage generated in the detection coil thereby capable of measuring strength of a magnetic field, the voltage having magnitude in response to strength of an external magnetic field, the method comprising: performing an in-rotating liquid spinning method to manufacture the amorphous wire; and performing removal treatment by immersion in an acidic liquid, performing an in-rotating liquid spinning method to manufacture the amorphous wire; and performing removal treatment by immersion in an acidic liquid, characterized in that: the method further comprising, after the in-rotating liquid spinning method, a subsequent wire drawing process to manufacture the amorphous wire, the removal treatment being performed for a process-affected residual layer generated at a surface and near the surface due to finishing by the wire drawing, the removal treatment being performed under a condition in which a wire diameter reduction rate with respect to a wire diameter before the removal treatment is 0.5-30%, a rate of the removal treatment for the process-affected residual layer is 10 micrometers per minute or less, the temperature of the acidic liquid being 10 to 60 degrees Celsius, and an amount of removal depending on a reduction rate of the cross-sectional area of the amorphous wire during the drawing process. the method further comprising, after the in-rotating liquid spinning method, a subsequent wire drawing process to manufacture the amorphous wire, the removal treatment being performed for a process-affected residual layer generated at a surface and near the surface due to finishing by the wire drawing, the removal treatment being performed under a condition in which a wire diameter reduction rate with respect to a wire diameter before the removal treatment is 0.5-30%, a rate of the removal treatment for the process-affected residual layer is 10 micrometers per minute or less, the temperature of the acidic liquid being 10 to 60 degrees Celsius, and an amount of removal depending on a reduction rate of the cross-sectional area of the amorphous wire during the drawing process.