Crystalline cephem carboxylic acid addition salt

A storage-stable compound in crystalline form selected from the group consisting of 7-[2-(2-aminothiazol-4-yl)-(Z)-2-methoxyiminoacetamido]-3-[5-(2-hydroxyeth yl)-4-methylthiazoliomethyl]-3-cephem-4-carboxylate sulfate, the crystals being characterised by the following X-ray diffraction data determined by the powder method using the copper K.sub..alpha. -ray, .lambda.=0.154 nm with an error in measurement of relative intensity within .+-.5% (in this Table, d indicates crystal lattice and I/I.sub.max indicates relative intensity):

• ______________________________________ Relative Relative intensity intensity Phase d I/I.sub.max Phase d I/I.sub.max ______________________________________ 111.11 100 3.81 61 7.02 60 3.74 86 6.10 29 3.69 39 5.75 24 3.61 79 5.03 24 3.53 59 4.69 92 3.40 38 4.51 27 3.35 32 4.47 38 3.25 30 4.38 42 3.15 83 4.31 76 2.74 25 4.00 32 2.67 35 3.96 27 ______________________________________