A method for measuring the area distribution of emissivity of a material surface, comprising the steps of - heating, by a non-contact heating heat flux, a heated area of the material; - measuring the area distribution of the radiated heat flux emitted by the material surface in a measured area at a specified time of area temperature homogenization in the course of non-stationary process during the cooling phase after the heating is terminated; - determining in individual places of an emissivity evaluation area the emissivity by calculation; wherein the heated area is the nearest unclosed area surrounding more than 270 up to 360 degrees of a circle centered in the emissivity evaluation area or wherein the heated area is the nearest closed area which surrounds the emissivity evaluation area, and whose photo-thermal properties of the surface are not affected by previous thermal or mechanical treatment; wherein the measured area contains the emissivity evaluation area; wherein the heating heat flux acts non-contactly from the same side of the surface of the material from which the measured heat flux area distribution is measured; and wherein the specified time of area temperature homogenization is determined in advance by measurement or computer simulation of the thermal heating and cooling process on the material standard and/or from the recorded time course of the measured heat flux distribution as the time when differences in heat flux in the emissivity evaluation area are minimal and/ or from the recorded time course of the measured heat flux distribution as the time when at a selected location, which is at least one point of the measured area of surface unaffected by previous technological process, the surface temperature reaches the reference value. - heating, by a non-contact heating heat flux, a heated area of the material; - measuring the area distribution of the radiated heat flux emitted by the material surface in a measured area at a specified time of area temperature homogenization in the course of non-stationary process during the cooling phase after the heating is terminated; - determining in individual places of an emissivity evaluation area the emissivity by calculation; wherein the heated area is the nearest unclosed area surrounding more than 270 up to 360 degrees of a circle centered in the emissivity evaluation area or wherein the heated area is the nearest closed area which surrounds the emissivity evaluation area, and whose photo-thermal properties of the surface are not affected by previous thermal or mechanical treatment; wherein the measured area contains the emissivity evaluation area; wherein the heating heat flux acts non-contactly from the same side of the surface of the material from which the measured heat flux area distribution is measured; and wherein the specified time of area temperature homogenization is determined in advance by measurement or computer simulation of the thermal heating and cooling process on the material standard and/or from the recorded time course of the measured heat flux distribution as the time when differences in heat flux in the emissivity evaluation area are minimal and/ or from the recorded time course of the measured heat flux distribution as the time when at a selected location, which is at least one point of the measured area of surface unaffected by previous technological process, the surface temperature reaches the reference value.