To discriminate a delay blasting electric detonator where detonation times are overlapped, to relieve the burden of a chemical managing worker at a site, and to perform the use of an efficient delay blasting electric detonator, by using a detonator shelf partitioned at each stage of a main stage and an auxiliary state.

This method is related to a managing method for an electric detonator in a multistage blasting method. A delay blasting electric detector comprises a main stage partitioned at intervals of a time of 300 ms, and an auxiliary stage corresponding to the detonation time of the main stage. Further, display to discriminate a constituting stage is displayed on the delay blasting electric detonator. Stage display of the delay blasting electric detonator at a first stage of the auxiliary state at the first stage of the main state is shown in Fig. The number of main states 6 is printed on a detonator case 1 and a binding tape 3 and the number of auxiliary stages 7 on the donator case 1 and a label 4. Numerals to be printed are changed according to the stage of each stage electric detonator. A detonator shelf used for management thereof is formed such that partition plates to partition a containing space at each main stage are laterally arranged and partition plates to partition at each auxiliary stage are vertically arranged.