In a radio communication system, an electronic component for high frequency power amplifier carries out the detection of output level, required for feedback control of the output power of a high frequency power amplification circuit, by current detection. The electronic component has an error amplifier. The error amplifier compares an output level detection signal with an output level instruction signal, and generates a signal for controlling the gain of the high frequency power amplification circuit according to the difference between them. For the error amplifier, a low-pass amplification circuit is used. The amplification circuit is provided with, between its output terminal and its inverting input terminal, a phase compensation circuit. The phase compensation circuit comprises a resistance element, and another resistance element and a capacitive element in series connected in parallel with the resistance element.