A phosphor having small reduction in brightness when exposed to the plasma, a phosphor paste comprising the phosphor are provided. The phosphor comprises the following fluorescent substances I and II, wherein the fluorescent substance I contains silicate and Mn as an activator and the fluorescent substance II contains a compound represented by the formula (1) or a compound represented by the formula (2) and Tb as the activator. (M.sup.1.sub.1-aM.sup.2.sub.a)(Mg.sub.1-b-cZn.sub.b)Al.sub.11-dMn.sub.c+d- O.sub.19-(a+d)/2 (1) [In the formula (1), M.sup.1 is at least one selected from the group consisting of La, Y and Gd, M.sup.2 is at least one selected from the group consisting of Ca, Sr and Ba, a is not less than 0 and not more than 0.6, b is not less than 0 and not more than 1, c is not less than 0 and not more than 0.5, d is not less than 0 and not more than 0.5, b+c is not more than 1 and c+d is more than 0 and not more than 0.5.] M.sup.3.sub.2O.sub.3.mAl.sub.2O.sub.3.nB.sub.2O.sub.3 (2) [In the formula (2), M.sup.3 is at least one selected from the group consisting of La, Y and Gd, m is not less than 2.5 and not more than 4.5 and n is not less than 3.5 and not more than 5.5.]