We have developed a head-mounted imaging device for measuring cortical brain activities. In previous studies, we designed the head-mounted imaging device equipped with a custom CMOS image sensor and realized long-term cerebrovascular observation in mice (Mark Christian Guinto et al., 2022, Journal of Biomedical Optics). In this study, we have improved this imaging device to allow two types of brain functional imaging: blood flow imaging and fluorescence calcium imaging. This imaging device has two colors of LEDs (Green: 535 nm, Blue: 465 nm) and a long-pass color filter (>500 nm). The green LED is used for the illumination light of blood flow dynamics imaging. The blue LED and the long-pass color filter are used for fluorescent imaging. The device weighs only 0.5 g. This device can be mounted on the head of the mouse without inducing undue stress during behavioral experiments by a head-mounted structure. We demonstrated brain surface imaging in mice. Using our system, we tracked blood flow dynamics and fluorescence intensity changes in the course of cortical spreading depression.