A method for manufacturing a high strength galvanized steel sheet having a tensile strength of 540 MPa or more, excellent stability of mechanical properties, formability, and coating appearance, characterized by comprising the steps of: applying a first heating step to a steel sheet containing C: 0.04% or more and 0.13% or less, Si: 0.7% or more and 2.3% or less, Mn: 0.8% or more and 2.0% or less, P: 0.1% or less, S: 0.01% or less, Al: 0.1% or less, N: 0.008% or less, and the remainder composed of Fe and incidental impurities, on a percent by mass basis, in which, in the former part, heating is performed in an atmosphere containing O 2: 0.1 to 20 percent by volume and H 2 O: 1 to 50 percent by volume in such a way that the temperature becomes within the range of 400°C to 750°C and, in the latter part, heating is performed in an atmosphere containing O 2: 0.01 to less than 0.1 percent by volume and H 2 O: 1 to 20 percent by volume in such a way that the temperature becomes within the range of 600°C to 850°C, and wherein the former part of the first heating step is performed with a direct fired furnace or a non-oxidizing furnace under the condition of the air ratio of 1 or more and 1.3 or less and the latter part of the first heating step is performed with a direct fired furnace or a non-oxidizing furnace under the condition of the air ratio of 0.6 or more and less than 1; applying a second heating step to the resultant steel sheet, in which holding is performed in an atmosphere containing H 2: 1 to 50 percent by volume and having a dew point of 0°C or lower in a temperature range of 750°C to 900°C for 15 to 600 s, cooling to a temperature range of 450°C to 550°C is performed, and holding is performed in the temperature range of 450°C to 550°C for 10 to 200 s; and applying a galvanization treatment, wherein an obtained galvanized steel sheet includes 75% or more of ferrite phase, 1.0% or more of bainitic ferrite phase, and 1.0% or more and 10.0% or less of pearlite phase, on an area ratio basis, the area ratio of martensite phase is 1.0% or more and less than 5.0%, and the area ratio of the martensite phase/(area ratio of bainitic ferrite phase + area ratio of pearlite phase) ≤ 0.6 is satisfied. applying a first heating step to a steel sheet containing C: 0.04% or more and 0.13% or less, Si: 0.7% or more and 2.3% or less, Mn: 0.8% or more and 2.0% or less, P: 0.1% or less, S: 0.01% or less, Al: 0.1% or less, N: 0.008% or less, and the remainder composed of Fe and incidental impurities, on a percent by mass basis, in which, in the former part, heating is performed in an atmosphere containing O 2: 0.1 to 20 percent by volume and H 2 O: 1 to 50 percent by volume in such a way that the temperature becomes within the range of 400°C to 750°C and, in the latter part, heating is performed in an atmosphere containing O 2: 0.01 to less than 0.1 percent by volume and H 2 O: 1 to 20 percent by volume in such a way that the temperature becomes within the range of 600°C to 850°C, and wherein the former part of the first heating step is performed with a direct fired furnace or a non-oxidizing furnace under the condition of the air ratio of 1 or more and 1.3 or less and the latter part of the first heating step is performed with a direct fired furnace or a non-oxidizing furnace under the condition of the air ratio of 0.6 or more and less than 1; applying a second heating step to the resultant steel sheet, in which holding is performed in an atmosphere containing H 2: 1 to 50 percent by volume and having a dew point of 0°C or lower in a temperature range of 750°C to 900°C for 15 to 600 s, cooling to a temperature range of 450°C to 550°C is performed, and holding is performed in the temperature range of 450°C to 550°C for 10 to 200 s; and applying a galvanization treatment, wherein an obtained galvanized steel sheet includes 75% or more of ferrite phase, 1.0% or more of bainitic ferrite phase, and 1.0% or more and 10.0% or less of pearlite phase, on an area ratio basis, the area ratio of martensite phase is 1.0% or more and less than 5.0%, and the area ratio of the martensite phase/(area ratio of bainitic ferrite phase + area ratio of pearlite phase) ≤ 0.6 is satisfied.