A respiratory abnormality improvement apparatus for applying to a patient at least one stimulus signal as an electric stimulus, comprising: a stimulus generating unit for generating the stimulus signal; and a detection unit for detecting a respiratory condition of the patient, wherein said stimulus generating unit is configured to generate: a first stimulus signal at a current level preset at a given time; and a second stimulus signal at a current level different than the current level of said first stimulus signal, based on a detection signal from said detection unit when the patient is determined to be under a respiratory abnormality condition, and wherein each of said first and second stimulus signals repeats: a conduction period (T1, T3) generating an electric pulse group having a current level higher than a given level; and a break period (T2, T4) generating an electric pulse group having a current level not higher than the given level or generating no electric pulse group, and wherein the conduction period (T1, T3) includes: a first interval (S1, S3) allowing the current level of said stimulus signal to rise in a manner that a rate of increase becomes gradually moderate with time; and a second interval (S2, S4) following said first interval (S1, S3) and allowing the current level of said stimulus signal to remain constant; characterized in that the stimulus generating unit is configured to insert a dither into said first (S1, S3) or second interval (S2, S4) of the conduction period (T1, T3), said dither causing the current level and/or a frequency of said stimulus signal to repeatedly increase and decrease. a stimulus generating unit for generating the stimulus signal; and a detection unit for detecting a respiratory condition of the patient, wherein said stimulus generating unit is configured to generate: a first stimulus signal at a current level preset at a given time; and a second stimulus signal at a current level different than the current level of said first stimulus signal, based on a detection signal from said detection unit when the patient is determined to be under a respiratory abnormality condition, and wherein each of said first and second stimulus signals repeats: a conduction period (T1, T3) generating an electric pulse group having a current level higher than a given level; and a break period (T2, T4) generating an electric pulse group having a current level not higher than the given level or generating no electric pulse group, and wherein the conduction period (T1, T3) includes: a first interval (S1, S3) allowing the current level of said stimulus signal to rise in a manner that a rate of increase becomes gradually moderate with time; and a second interval (S2, S4) following said first interval (S1, S3) and allowing the current level of said stimulus signal to remain constant; a first stimulus signal at a current level preset at a given time; and a second stimulus signal at a current level different than the current level of said first stimulus signal, based on a detection signal from said detection unit when the patient is determined to be under a respiratory abnormality condition, and wherein each of said first and second stimulus signals repeats: a conduction period (T1, T3) generating an electric pulse group having a current level higher than a given level; and a break period (T2, T4) generating an electric pulse group having a current level not higher than the given level or generating no electric pulse group, and wherein the conduction period (T1, T3) includes: a first interval (S1, S3) allowing the current level of said stimulus signal to rise in a manner that a rate of increase becomes gradually moderate with time; and a second interval (S2, S4) following said first interval (S1, S3) and allowing the current level of said stimulus signal to remain constant; a conduction period (T1, T3) generating an electric pulse group having a current level higher than a given level; and a break period (T2, T4) generating an electric pulse group having a current level not higher than the given level or generating no electric pulse group, and wherein the conduction period (T1, T3) includes: a first interval (S1, S3) allowing the current level of said stimulus signal to rise in a manner that a rate of increase becomes gradually moderate with time; and a second interval (S2, S4) following said first interval (S1, S3) and allowing the current level of said stimulus signal to remain constant; a first interval (S1, S3) allowing the current level of said stimulus signal to rise in a manner that a rate of increase becomes gradually moderate with time; and a second interval (S2, S4) following said first interval (S1, S3) and allowing the current level of said stimulus signal to remain constant; characterized in that the stimulus generating unit is configured to insert a dither into said first (S1, S3) or second interval (S2, S4) of the conduction period (T1, T3), said dither causing the current level and/or a frequency of said stimulus signal to repeatedly increase and decrease.