A simple energy scanning and data acquisition system for nuclear resonance analyses with a narrow resonance is presented. Ion beam energy was scanned by directly supplying a bias in the range -30 to +30 kV to a target holder. Details of the energy scanning and the data acquisition are described. Some examples for the depth profiling of nitrogen implanted into metals using the system with the nuclear reaction 15N(p, αγ) 12C at 429 keV are shown in comparison with the calculated results by a Monte Carlo simulation. The data analysis program used to obtain depth profiles from excitation curves is also shown. The target is divided into layers of uniform concentration and the reaction probability in a layer is calculated from a starting depth profile obtained from raw data, using the normalized error function with Gaussian approximation for the overall energy spread. This leads to a very simple computer program, fast to operate with a small computer.