specimen 17 namely the test specimen a test strip 18 having bands 19 20 21 formed by immune body reactions is illustrated as test specimen 17 in fig3 a test strip 19 is also run through scanner 7 as test specimen 17 to determine peak line 22 which is shown in fig3 b peak line 22 has three peaks 19 39 20 39 and 21 39 which correspond to bands 19 20 and 21 on the test strip a slope line 23 as illustrated in fig3 c is calculated from peak line 22 by computer 9 a fluctuation 19 34 on slope line 23 corresponds to band 19 fluctuation 20 34 corresponds to band 20 and fluctuation 21 34 corresponds to band 21 corresponding to amplitude 16 shown in fig2 c fig3 c shows a fluctuation range 24 bordered by dash dot lines fluctuations such as fluctuation 20 34 which are within fluctuation range 24 are below the threshold determined by threshold specimen 11 and are not taken into account in a comparison of slope line 23 of test specimen 17 with slope line 10 of reference specimen 1 after obtaining slope line 23 of test specimen 17 slope line 23 is compared with slope line 10 of reference specimen 1 by a pattern comparison performed in computer.