Coil device, pulse transformer, and electronic component

To provide a coil device having high bonding strength and bonding reliability.The coil device 1 has a core member 10 having a winding core and a flange 12, a wire 32 wound around the winding core, and a terminal electrode 52 connected with a lead 32a of a wire 32 provided to the flange 12; and an easy bonding layer 70 is formed on the surface of the terminal electrode 52 connected with the lead 32a in a stripe form 70a. the stripe form each bonding layer 70a is formed as a laser mark 71. In the coil device 1, a residue of coating film 78 which may be generated when the lead 32a of the wire 32 is connected to the mounting part 65 of the terminal electrode 52 is removed by laser.