Abstract: A needle threading device is disclosed which comprises a first mechanism having a hole for receiving a needle and a slit for receiving a thread, a second mechanism having a threader pin and pivotally supported by the first mechanism so as to be pivotable between a first position and a second position different from the first position, the threader pin enabling the thread to pass through an eye of the needle when the second mechanism is pivoted to the second position from the first position, a first biasing member urging the second mechanism to the first position, an operating member causing the second mechanism to be pivoted to the second position against an action of the first biasing member, and a second biasing member urging the operating member and the second mechanism in a direction in which they are spaced away from each other.