34CrMo4 steel used for cylinders for technical gases storage can be used for gases containing hydrogen, since it meets the requirements of NACE Standard TM0177-90. Microscopic investigations showed that the steel structure is a martensitic one. An influence of the applied stress Rsk (time to failure t) on the fracture character was analysed by the quantitative fractography methods. The presence of hydrogen was disclosed in a form of numerous microcracks.