The at least one ground terminal 30 is integrally molded to at least one of the upper dielectric body 15 and the lower dielectric body 16. A front end of the fixing portion 301 and the touching portion 302 of the at least one ground terminal 30 are fastened in the at least one lacking groove 18. The two upper ground terminals 31 are integrally molded to the upper dielectric body 15. The upper row of the conductive terminals 20 are located between the two upper ground terminals 31. Rear ends and middles of the upper fixing portions 311 and front ends of the upper soldering portions 313 of the two upper ground terminals 31 are molded in the upper dielectric body 15. Front ends of the upper fixing portions 311 and the upper touching portions 312 of the two upper ground terminals 31 are fastened in the two upper lacking grooves 153, respectively. Rear ends of the upper soldering portions 313 of the two upper ground terminals 31 project beyond the rear surface of the upper base portion 151. The upper touching portions 312 of the two upper ground terminals 31 project beyond a top surface of the upper connecting portion 152.