This report present the first characterization of the photon beam properties from SASE1 FEL at the European XFEL. Development of the amplification process has been traced from the level of the radiation pulse energy in sub-µJ level (beginning of high gain linear regime) up to mJ level (saturation regime). Experimental method is based on the analysis of single shot photon beam images allowing to derive spatial properties of the FEL radiation mode. An important conclusion is that experimental results demonstrate reasonable agreement with baseline parameters. Developed techniques of the photon beam characterization also provided solid base for identification of the problems and means for improving SASE FEL tuning and operation.