An imaging unit includes: a semiconductor package including an imaging device and having a back surface on which a sensor electrode is formed; a circuit substrate including a connection electrode that is connected to the sensor electrode via a bump; a surrounding part configured to cover the semiconductor package and the circuit substrate; a filler with which a space that is enclosed by the surrounding part is filled to seal a circumference of the semiconductor package and the circuit substrate; and a first cover configured to prevent the filler from infiltrating a joint between the semiconductor package and the circuit substrate.