A high pressure discharge lamp including a ceramic discharge tube defining
an inner space and having an opening formed within an end portion thereof,
an electrode system provided within the inner space, a sealing member
including a ceramic or a cermet with a through hole formed therein, at
least a part of the sealing member being fixed within the opening of the
ceramic discharge tube, and a metal member. A joining portion is
interposed between the metal and sealing members, and includes a main
phase contacting the metal member and an intermediate ceramic layer
contacting the sealing member and existing between the sealing member and
the main phase. The main phase includes a porous bone structure with open
pores, is made of a sintered product of metal powder, and includes a
ceramic phase impregnated into the open pores thereof.
