Recently, electron cyclotron resonance (ECR) plasmas has been investigated in order to be used for plasma processing technology. Here, the physical phenomena of the ECR-microwave discharge are numerically studied by a one-dimensional hybrid model of the fluid electrons and particle ions. The present model includes both the ECR heating phenomena and the transport of ions along divergent axial magnetic field lines. Microwave is considered as an energy flow attenuated by the thermal electron fluid. Individual ion motion is determined by ambipolar electric field and Monte-Carlo collisions together with the $\nabla$B force. In the fluid description of electrons, electron motions are coupled to the ions through ambipolarity and the energy transport is treated with the temperature equation. The argon gas discharges are simulated and the pressure dependences are analyzed for microwave power deposition, electron temperature, plasma density, plasma potential and ion energy distribution. The results of simulation are compared well with the previous experimental results. Especially the results show the two characteristic features of the measurements for the ion energy distribution: the low energy peak as found in the energy analyzer measurements and the high energy bump as found in LIF measurements. And the strong effect of the distributed ionization on the ion energy distribution is observed.