Energy is an essential requirement for continuation of economic development and preparation of human life's needs and comfort. In recent years, renewable energies, such as solar energy and fuel cells, have assumed prominent positions as clean and free-of-charge energy sources. Better power quality, high reliability, transportability, easy structure, etc., have increased the use of fuel cells in electricity production. In general, fuel cells are used in on-grid applications and in electric vehicles, uninterruptible power supplies, shipping industry, aviation, and space technology. One of the important aspects of fuel cell application is its input current, which must be as flat as possible, to improve the efficiency and to increase its lifetime. Another aspect is increasing the output voltage to the desired level. The present paper introduces a new combined circuit for the boosting DC-DC converter, which is very suitable for fuel cell applications. The following are amongst the advantages of the proposed circuit: its simplicity, its very high voltage gain without the need to using power transformers and without using maximum conduction periods of the switches and a considerable reduction in its input current's ripple. The proposed converter is simulated using MATLAB software package and the results, which prove its proper and desirable operation, are presented.