Elf magnetic field (Extremely Low Frequency) is a spectrum of electromagnetic waves whose frequency is 0-300 Hz. Sun is a source of life that emits its energy to earth in the form of electromagnetic wave radiation. This study aims to compare the radiation intensity of natural magnetic fields by the sun indoors and outdoors. The type of research used is experimental research. Measurement of magnetic field radiation intensity by the sun using EMF Meter and thermometer. The research was conducted from 06.00 – 15.00 WIB where the more daylight the temperature of the magnetic field and solar radiation increases, then the temperature and intensity decreases with the sunset. Data analysis techniques used using SPSS with data interpretation methods. The results showed that outdoor data had higher results compared to the data of indoor research results, namely the average indoor temperature of 29.5°C, 31°C, 32.36°C, and 31.7°C while outdoors 30.9°C, 32.9°C, 33.4°C, 32°C. The average indoor magnetic field is 0.044, 0.224, 0.262, and 0.326, while outdoors is 0.098, 0.324, 0.418, and 0.398. Research data shows that the higher the intensity of solar radiation results in the Earth's temperature, and the magnetic field gets higher.