[en] A complex of setups for measuring the lifetime of excited states of nuclei by the method of delayed electron-gamma and gamma-gamma coincidences in the range 10^-10-10^-6s is presented. The methods allowing for a substantial increase in the accuracy and efficiency of obtaining experimental data are developed. The procedures of measuring and analysing the multicomponent beta spectra with taking into account the instrumental effect which distorts the measured spectra are developed. Results of investigating the positron decay and determining the mass difference Qsub(B)+ for nuclei with Tsub(1/2)>20 min by the method of measuring the positron end-point energy are presented. The nano- and subnanosecond isomers for short-lived isotopes far from the beta stability line have been investigated. Probabilities of the electromagnetic transitions which depopulate the low-lying excited states in ¹⁵¹Tb, ¹⁵³Dy, ¹⁶⁰Tm, sup(157,159,161)Er have been determined and analysed. (author)